Along with the rise of information society, there is an increasing demand on various display devices. Usually, an image is displayed by a display device in a two-dimensional (2D) manner, so it is impossible to show depth information of a scenario intuitively. Along with the development of the computer information technology and the display technology, a three-dimensional (3D) display technology has become a research focus in the display field, and its operating principle will be described as follows. With respect to an identical scenario, different images are viewed by a left eye and a right eye of a viewer. Due to an interpupillary distance, two images slightly different from each other may be displayed on retinas of the left and right eyes of the viewer. This phenomenon is called as “binocular parallax”, and the two images form a “stereo image pair”. Then, the stereo image pair is combined in a brain's visual cortex, so as to provide a stereo display effect.